IN-SITU LYMPHOPROLIFERATION IN RENAL-TRANSPLANT BIOPSIES

A double immunohistochemical labelling procedure in paraffin-embedded renal tissue is reported in which CD3 was targeted as a T cell marker and Ki67 as a marker of cell proliferation. Proliferating and quiescen t T cells were unequivocally identified in situ, and their precise loc ation within the kidney was clarified by the use of periodic acid-Schi ff counterstaining to outline the basement membranes. Proliferating tu bular epithelial cells were also clearly identified. The results showe d that T lymphocytes proliferate within the tubular compartment during acute renal allograft rejection. Preliminary evaluation of the method in routine transplant biopsies indicated significant correlations bet ween histologically defined rejection grade and mean intratubular T ly mphocytes per tubular cross section and between proliferation of tubul ar epithelial cells and of intratubular T lymphocytes. The associated tubular epithelial cell proliferation may be a response to local damag e.